ahickman

I have a 94 22RE that has a knock when I let up on the accelerator during warm up. When the engine comes up to operating temps (5 minutes), the knock goes away almost completely. I read through a bunch of related posts, but can't differentiate between piston slap, worn bearings, wrist pins, or valve noise. Anyone suggest what this noise is most likely from?

SEAIRESCUE

In first 5 minutes, piston warms first. So, sounds like wrist pin or excess piston to wall clearance. You can figure out which cylinder it is by pulling the plug wires one at a time and cranking the engine. Get a second person to help. If its excess piston to wall clearance, drive it. You will be dead before it becomes a serious problem.

My $0.02

thook

Have you checked the timing? And, are you sure what you're hearing is an actual knock? Pinpoint where the noise is coming from, if you can.

ahickman

Timing is right on. I have gone so far as to advance/retard timing a bit to see if the noise goes away. It changes it a bit, but still present. I will get someone else to dip the throttle while I listen closely above and below.

bigarms23

check the valves

ahickman

Other than .008 intake and .012 exhaust, what would I look for?

DaveInDenver

Do you have a stick shift and does it happen only in certain gears? Thinking it could also be tranny noise, like a bad synchro, worn gears. I only mention it because I have a similar noise and I'm pretty sure it's not a worn wrist pin or out-of-round bore because I just built my new engine last year and the whole short block is only 8,000 miles old.